Here's How China Is Able to Censor WhatsApp and Other Chat Apps

This could be real blow for the future of encrypted messaging within the country.

Chinese censors on Monday blocked the mega-popular, Facebook-owned messaging app WhatsApp from being accessed by the country’s citizens. This move, which some experts think may be temporary, is being viewed as part of a larger effort to quell political unrest before the 19th National Congress of the Communist Party gathering scheduled for October.

This is hardly the first time the country’s ruling Communist Party have resorted to censorship in this way: China has been ranked the least-free country when it comes to internet freedom for the past two years. Facebook and Instagram have been banned there since 2009. But this latest effort is novel in how it was carried out and may suggest that China’s government has turned a corner in its ability to silence its citizens online.

Before banning the app altogether, the Chinese government appeared to be limiting the features it offered, starting with video chats and photo-sharing, reported to The New York Times. Now, it appears that even text messages are prevented from getting through. These have been widely-considered much harder to interfere with considering the kind of advanced data-transmitting method it takes the communications, which are encrypted-end-to-end.

Experts worry that this shift means China’s “great firewall,” as it has been called, can now prevent data that has been heavily encrypted from being shared. While blocking the use of certain websites and apps with the firewall has typically been accomplished with standard technical methods, like IP blocking, DNS/URL filtering, blocking the protocols that allow WhatsApp users to send encrypted texts likely requires a kind of highly specialized software. Speaking with the Times, applied cryptographer and digital censorship researcher Nadim Kobeissi definitively noted: “This is not the typical technical method in which the Chinese government censors something.”

This level of sophisticated blocking leaves Chinese citizens looking to share messages privately online with just one option, since using a virtual private network (VPN) to connect to a server outside Chinese jurisdiction. This is, however, both an illegal and unreliable method. This is a huge blow to Chinese privacy advocates since WhatsApp’s only true competitor within the country WeChat provides the government with user data.